Britney Spears was a bridesmaid for her cousin on Saturday (23.05.09).
The 'Womanizer' singer made a discreet appearance alongside her brother Bryan Spears at the wedding of Laura Lynne Covington, which was held at the First United Methodist Church in Amite, Louisiana.
A guest said: "When her brother walked her down the aisle, she looked stunningly calm and beautiful. She was very pretty, low-key. She was not the centre of everything, just pretty and calm and collected."
After the ceremony, Britney joined her sister Jamie Lynn – who was also a bridesmaid, and brought along her 11-month-old daughter Maddie – at the reception.
The source added to People magazine: "Britney sat at a table off to the side and visited with local people she knew.
"There was no fanfare. With all the star power Britney and her family command, it was still the bride's day."
Britney is currently taking a break after finishing the North American section of her 'Circus' tour.
Last week, she took her sons – three-year-old Sean Preston and Jayden James, two – to the Bahamas, where they stayed at the renowned Atlantis resort.
The 27-year-old singer has posted pictures of the break on her official website, showing her playing with her children in a swimming pool.